November 6, 2013

Artist’s representation of the “habitable zone,” the range of orbits where liquid water is permitted on the surface of a planet. The authors find that 22% of Sun-like stars harbor a planet between one and two times the size of Earth in the habitable zone. (Credit: UC Berkeley)

One in five stars in our galaxy like the Sun have planets about the size of Earth and a surface temperature conducive to life, astronomers at UC Berkeley and University of Hawaii, Manoa now estimate.

The estimate was based on a statistical analysis of all the Kepler observations of NASA’s Kepler space telescope of the 200 billion stars in our galaxy.

Given that about 20 percent of stars are Sun-like, the researchers say, that amounts to several tens of billions of potentially habitable, Earth-size planets in the Milky Way Galaxy.

“When you look up at the thousands of stars in the night sky, the nearest Sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye. That is amazing,” said UC Berkeley graduate student Erik Petigura, who led the analysis of the Kepler data.

“It’s been nearly 20 years since the discovery of the first extrasolar planet around a normal star. Since then, we have learned that most stars have planets of some size orbiting them, and that Earth-size planets are relatively common in close-in orbits that are too hot for life,” said Andrew Howard, a former UC Berkeley post-doctoral fellow who is now on the faculty of the Institute for Astronomy at the University of Hawaii.

Earth-size may not mean habitable

“For NASA, this discovery is really important, because future missions will try to take an actual picture of a planet, and the size of the telescope they have to build depends on how close the nearest Earth-size planets are,” Howard said. “An abundance of planets orbiting nearby stars simplifies such follow-up missions.”

The team cautioned that Earth-size planets in orbits about the size of Earth’s are not necessarily hospitable to life, even if they reside in the habitable zone around a star where the temperature is not too hot and not too cold.

“Some may have thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive. Others may have rocky surfaces that could harbor liquid water suitable for living organisms,” Marcy said. “We don’t know what range of planet types and their environments are suitable for life.”

Last week, however, Howard, Marcy and their colleagues provided hope that many such planets actually are rocky and could support liquid water. They reported that one Earth-size planet discovered by Kepler — albeit a planet with a likely temperature of 2,000 Kelvin, which is far too hot for life as we know it — is the same density as Earth and most likely composed of rock and iron, like Earth.

Transiting planets

NASA launched the Kepler space telescope in 2009 to look for planets outside the solar system that cross in front of, or transit, their stars, which causes a slight diminution — about one hundredth of 1 percent — in the star’s brightness. From among the 150,000 stars photographed every 30 minutes for four years, NASA’s Kepler team reported more than 3,000 planet candidates. Many of these are much larger than Earth — ranging from large planets with thick atmospheres, like Neptune, to gas giants like Jupiter — or in orbits so close to their stars that they are roasted.

To sort them out, Petigura and his colleagues are using the Keck telescopes in Hawaii to obtain spectra of as many stars as possible. This will help them determine each star’s true brightness and calculate the diameter of each transiting planet, with an emphasis on Earth-diameter planets.

Independently, Petigura, Howard and Marcy focused on the 42,000 stars that are like the sun or slightly cooler and smaller, and found 603 candidate planets orbiting them. Only 10 of these were Earth-size, that is, one to two times the diameter of Earth and orbiting their star at a distance where they are heated to lukewarm temperatures suitable for life. The team’s definition of habitable is that a planet receives between four times and one-quarter the amount of light that Earth receives from the sun.

A census of extrasolar planets

What distinguishes the team’s analysis from previous analyses of Kepler data is that they subjected Petigura’s planet-finding algorithms to a battery of tests to measure how many habitable-zone, Earth-size planets they missed.

Accounting for missed planets, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, allowed them to estimate that 22 percent of all sun-like stars in the galaxy have Earth-size planets in their habitable zones.

“The primary goal of the Kepler mission was to answer the question, ‘When you look up in the night sky, what fraction of the stars that you see have Earth-size planets at lukewarm temperatures so that water would not be frozen into ice or vaporized into steam, but remain a liquid, because liquid water is now understood to be the prerequisite for life?’” Marcy said. “Until now, no one knew exactly how common potentially habitable planets were around sun-like stars in the galaxy.”

All of the potentially habitable planets found in the team’s survey are around K stars, which are cooler and slightly smaller than the sun, Petigura said. But the researchers’ analysis shows that the result for K stars can be extrapolated to G stars like the sun. Had Kepler survived for an extended mission, it would have obtained enough data to directly detect a handful of Earth-size planets in the habitable zones of G-type stars.

“If the stars in the Kepler field are representative of stars in the solar neighborhood, … then the nearest (Earth-size) planet is expected to orbit a star that is less than 12 light-years from Earth and can be seen by the unaided eye,” the researchers wrote in their paper. “Future instrumentation to image and take spectra of these Earths need only observe a few dozen nearby stars to detect a sample of Earth-size planets residing in the habitable zones of their host stars.”

In January, the team reported a similar analysis of Kepler data for scorched planets that orbit close to their stars. The new, more complete analysis shows that “nature makes about as many planets in hospitable orbits as in close-in orbits,” Howard said.

The research was funded by UC Berkeley and the National Science Foundation, with the assistance of the W. M. Keck Observatory and NASA.

UPDATE Nov. 7, 2013:

“This is the first measurement of the prevalence of planets the size and temperature of Earth orbiting stars like our Sun,” Howard explained to KurzweilAI. ”This question has fascinated humans for the past century and indeed back to the ancient Greeks. Up until now, estimates were limited to philosophy, speculation, or extrapolation. We provided the first measurement based on the discovery of real Earth-size planets orbiting real Sun-like stars.

“Our result is pure knowledge about the prevalence of planets orbiting other stars. It does not have practical uses. The New York stock exchange will not budge a penny at the news about Earth-like planets. Still, all of humanity is richer. We become richer when great music is written or performed, or when great poetry is written.

“We are enriched, too, by insights we gain about our purpose in life and our contributions to future generations. The discovery of Earth-like planets puts our beautiful home planet into a cosmic perspective and gives us knowledge about our place in our Galactic community.”

Abstract of Proceedings of the National Academy of Sciences paper

Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration’s Kepler mission. We found 603 planets, including 10 that are Earth size and receive comparable levels of stellar energy to that of Earth. We account for Kepler’s imperfect detectability of such planets by injecting synthetic planet–caused dimmings into the Kepler brightness measurements and recording the fraction detected. We find that 11 ± 4% of Sun-like stars harbor an Earth-size planet receiving between one and four times the stellar intensity as Earth. We also find that the occurrence of Earth-size planets is constant with increasing orbital period (P), within equal intervals of logP up to ∼200 d. Extrapolating, one finds % of Sun-like stars harbor an Earth-size planet with orbital periods of 200–400 d.

Anybody ever been to Las Vegas? Man it’s hot. I couldn’t imagine living there a couple thousand or even a couple hundred years ago. Good thing we have air conditioners nowadays because boy it’s hot still.

Imagine an Earth colony on a hot desert planet. Can the settlers and their progeny adapt to the prevailing climate, even after considerable terraforming? Ken’s comments about Vegas point to such questions.

Wait — let me regain my composure after laughing uncontrollably until I had to take a breathing break!
Wow, that was the purr-fect “Mars Attacks!” clip. I would love to see a double feature of “Mars Attacks!” followed by “Starship Troopers”, preferably at a drive-in with authentic Atomic Age design sensibilities.

Though in theory I can rationalize everything, in actuality I only rationalize what I want to, when I want to … unless I am forced to. Then it gets pretty hideous. Get that? pretty/hideous ?? That is an oxymoron. How oxy are you today, leMMing? Oxygen. Still low on oxygen after that laughing fit. Oxygen, and beryllium. BeO, beryllium oxide, happens to be a compound which is isoelectronic with carbon. It says on Wikipedia that beryllium oxide, or beryllia, is a colorless solid that “is a notable electrical insulator with the highest thermal conductivity than any other nonmetal”. This could be useful as a dielectric material in capacitors.

Monkeys are primates, which are descended from rodents, such as lemmings. Perhaps lemurs are descendants of the missing link between lemmings and monkeys. Despite having relatively small brains, monkeys and their primate cousins such as humans have surprising brain processing power owing to the high fractal dimension of their convoluted cortices. But we all know that Martians are the undisputed kings of cerebral cortical convolution. You know, Martian cerebral cortex, sliced to perfection and strapped to fermented sake vinegar rice ball with a strip of roasted nori seaweed would make for fine nigiri sushi.

Do not waste your legal department’s time on this Earth-chauvinist mutant.
It would be more efficient to file a class-action suit against everyone on this thread so obsessed with life on all those Earthlike planets orbiting Sunlike stars.

Meanwhile those bots we landed on Mars seem to be telling us that there will not be any Martians until we get around to terraforming the place, possibly circa 2050.

was not only “spamming the site” but also off-topic on that article, and thus the editor can delete it together with my embarrassingly gradual.. i mean, embarrassing blunder of a reply like it never existed!…. err, nevermind, I think I’ve been agreeing too much with control freaks lately. Keep up the good work :)

It is very cool to hear that scientists are able to start finding or confirming there are more planets in our own Galaxy that might one day prove habitable for life. Please don’t confuse that idea with life already being there, or developing there on its own, anytime soon. I am not sure how any life can survive the overwhelming distances and the sterilizing effect of space to get there, but don’t let silly details get in our way of dreaming that one day we might leave Earth to survive the death of our own star’s demise (lets agree in just 500 million to 1.4 billion years from now we can expect the increase in heat from our own sun will boil off all the oceans. Heck some would argue that in just the last 4 years our global melting/warming has already started up on a surprisingly shocking pace thanks to the virus know as humans). Even if we migrate to Mars somehow and terraform it, to survive Earth’s demise, it should cheer us up that we are then on track 3-4 billion years later to have our Galaxy on a collision course with a much larger Galaxy, Andromeda http://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision

I want to disagree with the idea that there are 8.8 billion earth like planets that could support life in our own Galaxy as I have seen in similar recent articles. Here is one of 10 of them, this the NBC version http://www.nbcnews.com/science/8-8-billion-habitable-earth-size-planets-exist-milky-way-8C11529186 Here is a quote, “Astronomers using NASA data calculate that in our galaxy alone there are at least 8.8 billion Earth-sized planets that are not too hot or not too cold and circle stars that are just like our sun, according to a study published Monday.”

For starters, our sun is a G type main sequence star or yellow dwarf star and considered brighter than 85-90% of the other stars in our Galaxy. The formation of life needs energy as one critical component and why Red dwarf stars, I think, don’t put out enough energy fast enough to develop life well. When red dwarf stars http://en.wikipedia.org/wiki/Red_dwarf do put out enough energy, the orbits for habitable zones are so much closer that you often get tidally locked planets and thus frozen on one side, burnt on the other. To further make a negative point about life around red dwarf stars consider they often put out 1/10th to 1/10,000 the amount of energy of our sun.

OK, back to our G2V sun and understanding how hard it is to find an exact twin of our own sun in our own galaxy (click here for a few that get kinda close http://en.wikipedia.org/wiki/Sun-like ). In summary articles like this say, “Given that about 20 percent of stars are Sun-like”, implies 20% are just like our sun. I think it is closer to 7.6% and when you try to find one very similar, some might argue it is more like 2% or maybe way… way less.

Don’t forget that some argue the Galaxy at the center has too much radiation or if it is too far out it has other problems that don’t support life well. http://en.wikipedia.org/wiki/Galactic_habitable_zone Maybe there is only a 20% zone where solar system best develop or support life.

Then there are a few dozen other critical details that we are just starting to appreciate, like if maybe the star was at least a 3rd generation star, so that the elements contained in planets that form around them have heavier and more complex elements on the periodic table and thus more likely to support life. Our own star could be a 3rd or 4th generation star. There’s no way to tell exactly. It’s definitely not a 1st generation star however, due to the abundance of heavy elements in our solar system. However, since most supernovas go boom within a few million years, it probably isn’t a 2nd generation star either.

Then the planet needs to have liquid water and be able to sustain an atmosphere for a long period of time.We know Mars was missing a magnetosphere or ionosphere http://en.wikipedia.org/wiki/Magnetosphere and so the liquid metal core and size and density are are critical factors. Then of course you need some ideal percentage of water vs. land and maybe low level seas and of course tides to mix all those chemicals or ingredients for life. Maybe Earth is so special thanks to our Giant moon (some consider it so big it is almost its own planet) http://en.wikipedia.org/wiki/Giant_impact_hypothesis so maybe strong tides from the moon plus the combo of the sun were critical in life, or like the difference of a bank account that grows in value from compound interest, then maybe life on Earth got a boost in the same way (imagine this graph over 4 billion years vs. just 40 http://www.tvmcalcs.com/calc_images/formulas/Simple-vs-Compound-Interest.png)

Then there is the orbit and the speed and the axis… and so many other important factors… and a dozen others not even listed… and a dozen more we may not even yet appreciate how important they are. I guess I always see these articles that imply how many billions and billions of chances or expectations there are in just our own Galaxy that imply life is just boiling over. I think it helpful to see just how fast you can take a big number and turn it into just 1.

Lets guess high that there are about 1 Trillion total stars and planets that are in our galaxy. I want to play with the idea how fast or easy it is to take a Huge number down to just 1. What if Earth is the Only planet with intelligent life on it in our Galaxy? If that is true, then just how many factors or how rare are we? Back to our big number of 1 Trillion.

1,000,000,000,000

if you had to find an almost exact match to our Sun… Not too bright, not too old, too young, too small, to cold, etc so that it would produce the same amount of energy over the same period of time to help create life, it would be able to argue it is 1/100. Then it is just 6 factors of 1/100, or 12 factors of 1/10 that take the huge number to 1. What if instead of 12 important factors, there are 50 or many more? Even if there are 500 billion Galaxies total in the universe it is not hard to take that number to just 1 if there are 50 factors where it is 1/100 or 1/1000 that prove to be how rare life on Earth could be (or how rare intelligent life could be). They think there is one Septillion total stars in the known Universe, so even a number that massive goes all the way to 1 with less than 13 factors of 1/100. Some factors of course will be 1/10 or less, but some could easily be 1/1000 or more. but I think you get the point that Septillion to 1 in less than 13 factors of 1/100. Bam.

Remember red dwarf stars may live 10 Trillion years.. so just for fun lets pretend the life of the universe is at least that long. If the big bang was the start of the universe clock at 13.8 billion years ago.. and end of that clock is 10 Trillion, then maybe a way to see it is that we are at the very, very start of the universe overall (One tenth of the first 1% or 0.001), so No I don’t think Earth is the only planet in the Galaxy with life, but I do think we are the Only one with intelligent life. I don’t think we are the only one with intelligent life in the Universe, but what if we are first… or first by a few billion years. Two reasons for Fermi paradox. #1 there just are not any others in this galaxy (yet) and #2 we are just too very, very, very far apart from anyone else to ever hear from them.

Today I awoke, drank some coffee, read Gator’s post and started thinking about human technological virtuosity advancing to where the death of our sun would not matter too much because by that time, humans will have been constructing artificial stars with very habitable planets for millennia by then.
Swords into plowshares. Hydrogen bombs into synthetic suns …

Drives me crazy when I see scientists say how they find life in places on Earth they don’t expect… bottom of the oceans, or under rocks in the desert.. and Somehow this proves how tough life is and thus life can develop on other planets with extreme environments also… Nope! Not the same thing to find it in extreme environments when the earth is already exploding with life to easily restock or spread it. Not even close to the same thing…sorry. I think we have to stop making that huge logic jump that because we find life on earth it has to be everywhere in the universe. At a bare minimum you need the warm shallow seas (with some land masses) where the right combo of chemicals easily mix over millions and millions of years. Toss in a fairly stable atmosphere and magnetic shielding and steady energy source like our sun, then come talk to me about life forming. If you have a big gas planet…you’re out. No life for you. If you look like Mars and are a big desert… no life for you. If you are a moon and not a planet…No life for you. If you are too close to your star… No life for you. If you are around a red dwarf… No life for you (*not unless you wait a few hundred billion years..maybe). If your planet it tidally locked, then no life for you. If you don’t have magnetic shielding or no atmosphere, then no life for you.

One other myth needs crushing… Meteors or comets are Never… ever going to spread life from one planet with life to another without. Yeah they may transfer some chemicals that help somehow if you are missing heavy elements (lets agree that is a different idea, but still a long shot)..and yeah we do have proof we have found meteorites from mars or the moon on the earth, so chunks have gotten knocked off and landed here on Earth eventually, but space is the most sterilizing environment for life there is, so forget the cool movie shot of green goo oozing out of a meteor and spreading alien life here or anywhere. Won’t ever happen… anywhere in the total universe… ever.. stop it. Just get back to building spaceships full of lifepods that seed other planets or self terraform… that idea might work if you could ever get them where they need to go…

Thanks for that link… If I understand what they are doing, they are gathering lots of data to help find some norms, then guess what other solar systems we can’t yet see must also have. Note that of the 3,538 potential worlds they found, 674 were the size of earth, so only 5.3%. Not sure where all the smaller than Earth sized planets are… (maybe they can’t see them yet, or maybe they end up in the Same as Earth pile…? maybe our Earth percent drops once they actually factor all this mini planets in). I would argue that planets too small are less likely to create life, or hold the environment to support life for billions of years needed to create intelligent life. In summary it is cool that they can start to use these norms to calculate how rare an Earth sized planet would be around certain star types and make me think Earth sized planets in the habitable zone are rare.

…what I took away from that article was in this quote “For the first time, astronomers have been able to estimate that an astonishing 90% of all the stars in the galaxy formed during the first 4 billion years. During those early years, stars were created 15 times more frequently than today.”

and knowing our Sun was not part of that 90% group makes us in the opposite or 10% pile… or maybe one more thing that makes our Earth rare or different. If you need heavier elements to help create life and 90% of all the stars are first gen stars… or red dwarfs.. then maybe less chance of life around those (yet of course… maybe a small batch turn into 3rd gen or beyond eventually…? Maybe with less star formation occurring the chance of new 3rdGen stars+ is drastically dropping off).

..again… I am not saying Earth is the only planet with life, or with intelligent life… just that I would guess we are very, very early in this process… if it takes a 3rd gen type star and a planet like ours with a giant moon, and liquid water with an atmosphere that lasts 4.5 billion years or more…to create these levels of complexity that are required, then maybe we could be early on this total curve of when intelligent life becomes possible anywhere else in the Universe.

Maybe you need on average 7 billion years to create a life form so advanced that it creates the ability to create a spaceship to leave their own planet. Maybe in our case we got lucky and did it in 4.6. Note at the 5 billion mark of any sun like system your temp heats up and maybe all water boils off and you burn up..so anyone with an average above 5 billion never makes it. Maybe one very tiny factor (like how big your Moon is) affects the tides in the exact same way compound interest affects a bank account value (think in billions of years for compound interest of course). Maybe an Earth like planet with Exact features minus that 1.. never makes it, or makes it so late it is irrelevant. I bet in our Milky Way, they can’t find a single Earth sized planet with a Moon as big as what Earth has in the habitable zone. http://en.wikipedia.org/wiki/Giant_impact_hypothesis

What if the meteor that killed the dinosaurs 65 million years ago never hit and mammals never needed to evolve? Would we all be lizards still…? maybe you need a few dozen mass extinctions, but just 1 too many and that planet never develops intelligent life, or if it does it is too late to survive their sun’s expansion.

ok. last cool link. This one is really worth a look if you have not yet seen it. a Ted.com video. Backed by stunning illustrations, David Christian narrates a complete history of the universe, from the Big Bang to the Internet, in a riveting 18 minutes. This is “Big History”: an enlightening, wide-angle look at complexity, life and humanity, set against our slim share of the cosmic timeline.

Good point you make about the importance of Earth’s strikingly huge Moon as orbital counterweight and tidal flyweight helping conserve our atmosphere and with it, overall life-friendliness.

If the Cretaceous Period meteor hit did not happen, and there was no dinosaur-extincting climate catastrophe, we would not still be lizards; “we” simply would not be – at least not as we know us. I did get this funny mental image of an intelligent lizard species evolving that bore a strange resemblance to the Geico gecko, not that I am implying in any way that the development of an insurance industry is any metric of the intelligence of any species.

..good point… On a side note…. I don’t think asteroids re-seed a planet with life once it is lost.. So maybe once it is gone, it is gone. It will prove very interesting if they can find any evidence of life on mars as it seemed to have liquid water and a few other important parts, yet clearly things changed there and life had no real chance to advance

In A.A. Attanasio’s mind-blowing novel “The Last Legends of Earth”, an almost incredibly advanced species uses fossilized DNA from a dust cloud which was all that remained of our Solar System billions of years after our Sun exploded several billion years from now, to stock a synthetic solar system’s artificial planets with re-created Earth life (including humans) to serve as bait in a trap for killing their own intergalactic natural enemy life form.

Gator said:
“…you’re out. No life for you. If you look like Mars and are a big desert… no life for you. If you are a moon and not a planet…No life for you. If you are too close to your star… No life for you. If you are around a red dwarf… No life for you (*not unless you wait a few hundred billion years..maybe). If your planet it tidally locked, then no life for you. If you don’t have magnetic shielding or no atmosphere, then no life for you.”

The tidally locked worlds near a red dwarf will most likely end up like our own twin, Venus. She barely turns at all, and that in the backwards (retrograde) direction. Her year is 225 of our days, but her day is 243 of ours.

You’d think she’d be cold on her dark side, but she has fierce high-altitude winds of tornado speeds. So her temperatures are equal from pole-to-pole, front-to-back.

…Thanks GR for the red dwarf details… Those stars seem to last for ever… I just wonder if they are so different from our type of sun that they don’t create the chance for life in the same ways… or at all. Maybe astronomers will end up changing our terms for habitable zone a few times until we figure these things out better…

I’ve been trying to create a huge mass of PURE water in my intergalactic backyard.. you know, to spend time in the pool with the kids and such, so they lose that greeny tan.. but I haven’t managed yet to make it pure floating liquid, the pressure always solidifies into ice at the core and if I try reducing the volume, gravity won’t hold it together… well, I guess I’ll have to have a small, extremely dense, pool floor then.. shame.. I’ll have to settle for laminating it with roman marble.

We are only the colllapse of a quantam wave in the thought of a intelligent mind pushing the limits of our quantum reality! Currently being pushed by
Stephen Hawkings until the rest of us join in the collapse!

Coded gamma pulses like those from low alt lightning strikes on earth would propagate through the interstellar dust clouds…..think of directed microwave com on earth. Highest frequency and energy for ET com. Our gamma surveys should contain digital information now for SETI!

Gamma-ray bursts would be another carrier. They only last minutes, but perhaps a type III (or above) civ on the Kardashev scale would want to share their information. We could calculate the max information transfer based on the frequency and the time available for the transmission.

I want to go to the one that’s only 12 light years away if it’s also not the one with a surface temperature of 2000 degrees. (unless I am allowed to carry an air-conditioner on board without having to pay for excess baggage) Traveling at half the speed of light 24 years wouldn’t be all that long and better than being locked up in solitary confinement for life for doing something I would never even dream of doing. I think the spaceship can be built within budget and according to the PERT chart and the NASA specs. The Federal Reserve can print up the money for any significant cost over-runs. The auxiliary space ship will of course carry all the necessary water, food and oxygen for the 24 year trip plus all the necessary terraforming equipment and bacteria. (we don’t have to worry about any return trip because life will be so good on planet X once we have finished terraforming it that we will never miss planet earth. The spaceship will have a lead shield 50 feet thick to try to screen out gamma rays and too many neutrinos so that we won’t be fried or have cancer by the time we get there. Any Twitter messages we send back to planet earth mission control will only take a few light years to get there but there won’t be much need to say anything and even less to “follow” anyone. I am ready to go but I may not be able to afford the price of the ticket. Could I be financed thorough crowd-funding?

Your enthusiasm is laudable, Eager2GO. But the shielding doesn’t need to be 50 feet of lead. Back during the Cuban Missile Crises we were advised that 18 feet of concrete would stop gamma rays. So a like thickness of rock from asteroids will be sufficient.

It will not be long, say 10-20 years, before we will be mining asteroids (take a few seconds to laugh at me laughing at myself for almost typing that word as ‘asterrhoids’!) on an accelerating scale. A mining protocol can be developed such that the most promising drill cores from the surface lead to ore bodies which are hollowed out, creating vast chambers for crew living space with lots of plants providing oxygen, food and medicines as well as roses to smell and other flowers to enjoy; we will also need interior space for life support, mechanical infrastructure supporting robots for making 3D printers, computing equipment, PV panels, astronomical observatory sensors and telescopes, and more robots. A rind of intact rock will be preserved so as to provide for Gorden’s shielding. Many of the original drill holes from the surface will be fitted for excursions to install and repair PV power units and propulsion systems. As asteroids become starships and moons become space stations, a never-ending armada from Earth and its solar system sets out to explore and colonize the galaxy …

Hey Gorden – here we are chatting in close to real time!
I love the idea of those “rock ships”. They have been a staple of science fiction for 50 years or so, and now we are at the threshold of realizing them.
Do you suppose we might find an asteroid (preferably profitably minable) that would be large enough and of a shape suitable for housing the more complex machinery sufficient so support interstellar travel? I am thinking, as you say, “miles across and hundreds of miles long”. Actually, there are quite a few big cigar-shaped asteroids fitting roughly those dimensions.
I also like your idea of iteration upon iteration of robots, 3D copiers and PV arrays out there building space-based particle accelerators. We will just have to be sure to failsafe them so that rogues, pirates and terrorists cannot hijack them and repurpose them as weapons.

Good thinking, Trance_Ender. I foresee that switching over to the hydrogen economy will end a lot of terrorism. When the West no longer needs the oil of the Middle East, we will lose a lot of our interest in Saudi Arabia. After that, a lot of the terrorists will lose interest in killing us.

In Russia we met some scientists working on the still not fixed Chernobyl disaster. I asked if there was a solution and they said “Sure, pour 5 feet of concrete over the whole thing,”. So why didn’t they do that? They were scared someone would interpret that as having a “problem” and besides, the govt was buying gall the food raised near the site and destroying it. LOL

“…At NASA Langley, Thibeault and her colleagues are testing new types of shielding that consist of hydrogenated materials. Hydrogen offers protection because it breaks apart heavy charged particles without creating secondary particles that add to the radiation dose, she notes. One of the materials under investigation, hydrogen-filled boron nitride nanotubes…”

I have another question. The principal behind most accelerator experiments is to accelerate particles to near relativistic speeds and then slam them into each other. What happens when we accelerate a spaceship to near relativistic speeds and it slams into these cosmic rays, which are also energized to near relativistic speeds? I can only imagine it would impart tremendous energy into whatever shielding we might invent. It seems to me that those baseline levels of cosmic rays would increase to unimaginable levels.

That would inrease the mass to unacceptable levels. The energy might be havested some how, but don’t worry, as we get more understanding of the quantum level, we’ll find another way. It’s really just information that needs to be sent. Entanglement and the Einstein Bose condensate hint at another level.

@Amara: your links have spawned some questions. This might get a little convoluted as I set up those questions. There are several.

On a questionable website, I’ve seen images of our magneto pause, recording what looks like an impact similar to the solar wind, but coming from the opposed side. It was related that NASA hid the story. So my question here is, how much do we know about the relative levels of extrasolar cosmic rays? It seem from your Lin that our knowledge isn’t very indepth. The images of this extrasolar event were of a powerful influx.

Secondly, I imagine that the strength of our magnetic shields is relatively low. That it achieve it’s shielding effects from it’s relative size. I also expect that increasing the magnetic strengh would increase it’s protective effects. Is there any research into creating a similar shield for space craft?

Brookhavens collider is using gold ions for collision experiments, because the higher mass.( protons and nuetrons). These are also directed by magnetic fields. These ions are brought up to fairly high emetics and yet we can still steer them. The third question is, could we theoretically use similar magnetic fields to shield against extrasolar cosmic nuclei?

The last question is in reference to metamaterials. Since an atoms properties are largely the result of it’s electron shells, and since the hydrogen boron nitrate shows great promise. Is there any theoretical work on other unique combinations of materials that would be more capable of absorbing these energetic cosmic rays? Maybe even harvesting these energies to create usable energy?

Sorry for so many question at once. Perhaps there might be some future articles on these topics.

Extrasolar cosmic ray influx sources could be:
1. the black hole at the center of our galaxy;
2. “Active galactic nuclei” (essentially supermassive black holes) close enough to matter (pun somewhat implied) directionally oriented such that one of its polar jets point in our direction.

I happen to live in Brookhaven, a town that would be a state in a county that could easily be a state in its own right. Most Google Maps aerial photos of the Brookhaven area show a ring-shaped megastructure slightly east of center. That is Brookhaven National Laboratory’s Relativistic Heavy Ion Collider, a smallish predecessor to Europe’s Large Hadron Collider, with which Team CERN scientists recently detected the elusive Higgs Boson. Yes, Brookhaven is using GOLD ions as projectiles, for 3 main reasons:
1. they are heavy, at 197 times the mass of protons;
2. they are much less toxic than lead or mercury;
3. BECAUSE THEY CAN, being an imperial government facility.

15 years ago I had the opportunity to tour the facility with a local high-tech industry trade group, just after the facility became fully operation. I asked the “Why Gold?” question and was given answers 1 and 2. Too bad it did not occur to me then to ask a third question, “Why not tungsten, which is almost as heavy an ion as gold and much cheaper?” Besides, back in those days, I was much more interested in the workings of the graphic displays of their detectors. The RHIC machine can very accurately target opposing rays, or streams if you prefer, squarely at each other through the use of huge superconducting electromagnets they keep improving upon. Keeps Brookhaven Laboratory’s and Stony Brook University’s material science faculties endlessly busy and happy.

Regarding interesting materials, BN (boron hydride) seems unusually promising, almost as promising as that 3D hexagonal-crystalizing metallic carbon allotrope. BN molecules would feature a lattice (my first crude guess would be isomorphic) of B – N dipoles, each of which with their completed inner electron shell probability clouds closely surrounding the B and N nuclei, surrounded in common by one completed outer electron shell/cloud of 8 electrons, 3 of which contributed by the boron, 5 from the nitrogen. I have a feeling BN would manifest in at least 2 allotrobes: metallic and diamondoid. There could also be cylindrical nanotube and graphene-like sheet varieties. Please note that I am looking at these from a mostly mathematical perspective.

I have a feeling Bri is thinking of a material that could convert incident cosmic ray beams into electricity, analogous to what currently utilized (yes, pun implied) PV panels do with photons. Except here we are dealing with particles which have mass. Suddenly Einstein’s work involving the photoelectric effect comes to mind with David Bowie’s “Turn your ‘lectric eye on me babe” playing in the background. My mind is a time machine jukebox.

Your from longuyland? Me to! Freak out in a moon age daydream (David Bowie). Amara’s link stated that the hydrogen was used because it had preferable byproducts from high energy collisions.

On a slight aside, I found a piece of a meteorite in a Home Depot parkinglot. At least it most likely is. At the rock and mineral shows, I’ve had people look at it. It’s odd shape is the tell. The only way to know for sure is to cut and polish a clean face, and then etch it with nitric acid. If it’s real ly meteoric iron it will have a crystalline pattern from the slow cooling.

I’d love to explore the asteroid belt just to see it’s structures and composition. I don’t know how large the single crystal partitas become in iron based asteroids. Some of the etched slices I’ve seen indicate they might get quite large. There is so much that we could learn about the conditions of the proto solarsystem. I’d love to see a comparison of those characteristics between the contents of the asteroid belt and whats in the Ort cloud. It would be like CSI on the birth and death of solarsystems and planetary formation.

Yes, Bri, I am also from this strange fish-shaped world-within-a-world.

I wonder, how can hydrogen have much in the way of by-products being that it is so simple? Just protons and electrons, plus the occasional neutron contributed by the heavier isotopes. I suppose they use the hydrogen plasma particle yields for experiments involving proton and electron accelerators, which are much more economical to run than the golden RHIC.
I vehemently agree with your assessment of meteorites, asteroids, the asteroid belt and the far-out Kuyper and Oort clouds as great scientific playgrounds from now into the near-to-mid future.

Another fleeting Bowie reference:
Everything I need to know I get from my TVC15
(which would most likely be some sort of “smartphone” or tablet device).

Isoelectronicity – the same principle behind the properties of gallium arsenide which make that compound so useful in high-performance semiconductors. As is revealed in the Periodic Table Oracle, if you pair up atoms from Column 3 {B, Al, Ga, In, Tl} with atoms from Column 5 {N, P, As, Sb, Bi}, you can make compounds that are isoelectronic with elements in Column 4 {C, Si, Ge, Sn, Pb}. 21st century alchemy here!

……so what if we could change our DNA so that cosmic rays were used as energy for our bodies vs. doing damage. Maybe like how plants use photosynthesis….? All this shielding seems complex or at least heavy and thus hard to get going at the some fraction of the speed of light if built into spaceships.. maybe the problem is just an opportunity in disguise? I keep wondering what will happen to those that try to live long term on Mars and have only 38% gravity vs. what we have on earth and what damage that will do to our bodies? Also they will need special shielding there… since we will need to repair our bodies in new ways just to survive there, and since we are working on new ways to improve our health and lifespan.. why not just learn to reprogram and regrow what we need… assuming there is Cosmic energy damage or use it as an energy source of some new kind.

Hey Gator! There must be a way of taking energy from cosmic rays, and it just might involve quantum magic as we see in photosynthesis. But cosmic rays just might be too energetic for DNA. It would be interesting to see what could be done with alternating layers of graphene and BN.

Cool idea… yeah, maybe some form of high tech solar type panels we wear as clothes… vs. try to let our skin do that part. Maybe just need to reprogram our healing cycles to repair that type of damage, so we live forever.. or live healthy as long as you need.

Since 90% of cosmic rays are hydrogen nuclei, advanced nanobots should be able to repair their damage almost instantly. The most energetic cosmic rays should be from the heavier elements, but they are only 1% of all cosmic rays, so you should have time for your nanobots to heal their damage too.

You needn’t limit yourself to only half light-speed, Eager. You can go as fast as whatever you are shooting out of your tailpipe. The Large Hadron Collider can accelerate particles right up near the speed of light now. So an immense charged particle accelerator can get you right up close to the speed of light.

I’ll leave my fleshie here on Earth and E-mail a copy of myself to an unused robot waiting up there just for me. The fee won’t be very high. When robots are building robots out of asteroids and the regolith of the moon, they will be dirt cheap.

Gorden, you have once again given us a peek at a realistically feasible post-Singularity future more fun than science fiction. Imagine all those asteroid starships going forth from Earth in all directions to seed the galaxy … and beyond …… Why? Because humans seem to be coded for exploration and habitat extension. It sure beats the post-apocalyptic vision of exodi and interplanetary diaspora of refugees from a wrecked Earth desperately searching for a new home.

Let’s say that this OM 10 (ten to the tenth, 10,000,000,000) estimate is about right. We need to know: what fraction are in quasi-stable (5 billion year stable), nearly circular orbits. Of that, what fraction are orbiting stable, lucky stars, ones that are not highly variable or prone to large X-ray storms, and have never been near (within light years of) novas or the remains of them, or near X-ray pulsars or any of the other sterilising forces in the galaxy. Of that, what fraction are not mainly gas. Of that, what fraction has an atmosphere. Of that, what fraction has enough hydrogen that water could be present on the surface. Of that, what fraction also has enough of the other elements of life on its surface. Of that, what fraction has life sufficiently advanced to have an oxygen-nitrogen atmosphere.

At this point we’re down to OM 4 or less: maybe 10,000 habitable planets, if we’re lucky. If there’s intelligent life out there, it’s likely to be thousands of light-years away.

Well of course, tom. You must have heard of all those extremophiles, like the sulfur bacteria that live in the boiling hot springs of Yellowstone, or those other bacteria that live on arsenic at Lake Mono, or all those bacteria that live down in caves and very deep down in mines.

We have to stop wrecking this world now. We can’t wait until the Singularity to move over to the hydrogen economy. We have to push on to the mass marketing of the cheap, efficient, printable carbon photovoltaics.

When electricity is cheap enough, we can afford to split water into hydrogen and oxygen for heating and cooking and transportation.

We will be able to start building a lot of robots and mining vessels out in the moon’s orbit in the next 15 to 20 years…but only if somebody with the money has the will to do so.

But the robot pink-slip apocalypse will also arrive at this time and there will be terrible social problems to deal with.

It occurred to me that the robot pink slip apocalypse also has the potential to free dreamers to dream and, with ever more versatile 3D printers and copiers rapidly plummeting in price, ever more capable of realizing their dreams.

Yes, Trance_Ender, that will be the good part…but only if we are all getting our Unemployment Insurance or Social Security checks. Even that won’t be the life of Riley — those checks are small. But as long as they keep coming, people will be able to scrape by and society won’t collapse. And some people will rise again. Col. Harlan Sanders started his Kentucky Fried Chicken franchises with his first Social Security check when he turned age 65.

After a little more thought of what you wrote, Trance_Ender, I thought about bright young people from the Barrio or the ‘Hood getting together with their ideas online and then taking them to an independent repair shop downtown that has a 3-D printer and starting their own little business.

You have basically summed up this life of not-Riley I am living. I find that I am having to cultivate the skill set of a zen master in order to live within my more than somewhat limited means, though what is really rich, priceless in fact, is that most of my time is all mine.

Not necessarily, though perhaps human culture would do well to explore simulations (for which we have many examples of OCP from Earth history) so as to better devise effective plans for placing ourselves in a position somewhat better than the wrong end of an OCP.

Any technological species “if they live long enough” should be able to colonize the GALAXY given enough time (say billions of years) – even at sub light speeds.

Look at us. We have already launched primitive drones (voyager) that have reached interstellar space. We have been broadcasting radio waves for 100 years. In a thousand years, if we haven’t extinguished ourselves, what will our reach be? 10,000 years?

Our solar system is roughly 5 billion years old and the age of the universe if roughly 13 billion years. one could make the argument that if life is as common as it now appears, an intelligent technological species could have evolved 10 billion years ago and spread across our galaxy leaving remnants of its existence. Instead there is…silence.

Either we are the first within our own galaxy to develop technology (possible but unlikely) or there is a great filter (probable) which does not bode well for us.

I have to regretfully agree. In less than 100 yrs we went from horses to traveling outside the solar system. The future is unimaginable so if there were only 10 (from the billions of Earthlike worlds) sentient races who finally discovered the workings of the universe, why isn’t Earth colonized? Why no. Alien structures in our Solar System? THEIR robots should be flooding the galaxy yet nothing – no signals, ruins, signs in the sky, structures…

“Why isn’t Earth colonized?”
From what they can see of Earth from their locations, Earth may not appear to offer whatever would make it worth their while to visit us. Then again, they may already be on their way.

The Goldilocks zone is fine, if you are only concerned about liquid water. But what about gamma radiation from the planet’s star? Earth has a magnetic field that deflects most of our ‘cosmic’ radiation, generated by the currents of Earth’s metal core. Therefore, finding a planet worth visiting, solving for traveling the distance, includes a planet with an orbital distance for liquid water, the right size/mass for a gravity to hold its atmosphere, an orbit stable enough to allow life forms to evolve and a magnetic field to guard against too much radiation exposure. I am sure I have missed a few elements/factors for a life sustaining planet, but the 8 billion is only for one of the most critical elements. Unless you are including planets where extremaphiles can survive and not just humans.

Right Steve. There are so many factors to consider, so many conditions that must be met, that having life like ours on a world is like winning the Power Ball. Sure, when there are enough tickets sold over a long enough time, somebody is bound to win. But a great number of the ticket holders are losers.

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So for the short term, we still have to keep people from ruining the Earth for life. One way is to keep pushing for cheap, efficient, printable carbon photovoltaic cells that can make electricity at a low enough cost for it to be profitable to split water into hydrogen and oxygen to fuel all of our motor vehicles.

Could the great filter be something other than it appears. In other words, perhaps at a certain level of technology species are working in non-physical dimensions so that we cannot detect them or simply in dimensions that we cannot currently access? Or perhaps when species reach a certain stage most of their activity is within computers and thus difficult for us to detect? Or perhaps when they do explore, their probes and ships are very small and for this reason we cannot detect them. They might be making concerted efforts to minimize their interference with their environments in a sort of high tech environmentalist approach and thus we have trouble detecting them. What about these possibilities, that we can’t detect them in the same way pre-modern societies would have no way to detect our radio signals? What do scientists say about possibilities that like these to explain Fermi’s paradox?

All possibilities. Whatever is not impossible becomes inevitable. I am reminded of the United Federation of Planets’ “Prime Directive”, a strict noninterference mandate forbidding any contact with aboriginal cultures insufficiently technologically advanced to have developed their own transrelativistic (faster than light speed) propulsion systems.

You’d think all the whiz guys would have considered those very logical and natural questions. I’ve always thought it rather silly that we look for other sentient advanced races assuming they use our current technology

Actually if you are headed on a one way trip, relativity makes the trip shorter through time dilation. Its only if you are worried about how old people are when you get back to Earth that relativity becomes a problem.

But really relativity makes interstellar travel no more or less practical as the amount of energy and reaction mass required to reach speeds where relativity is a factor are immense.

The fate of the native fauna is uncertain when an apex predator species is introduced, no matter how cheerfully they’re welcomed (see history of apex predator conflict on this planet, i.e., explorers/settlers vs natives).

That’s another thing to consider, anon. If a world has apex predators much better than the lions, tigers, and leopards of Earth, then the primates that would have evolved into humanoids might have been all eaten up before they discovered how to make flint spear points.

That ur-humanoids on Earth survived long enough to surpass the intelligence of lions, tigers and leopards (and do not forget old smilodon) that our philogenic ancestors did not all become cat food is in itself somewhat miraculous.

If you are interested in learning why aliens are not visiting us, you should check out
Seth Shostaka’s, of SETI’s, speech from a Singularity University session: http://youtu.be/SFFi3sWq5jE

It has been a few months since I heard the speech, but as I recall he said the reasons were something like this:

1) Intelligent Aliens tend to evolve into powerful AI, and then they congregate near high energy areas of their galaxy/universe.
2) Planets are so far from each other, such trips are not worth it.
3) Maybe they are already here, but at such a tiny scale we don’t even realize it, or observing us through ways we could not imagine.
4) Just like we don’t seek out and visit (nor destroy) every ant hill we see, Aliens won’t do the same to other planets. So the analogy is Powerful AI aliens: Humans as Humans: Ants

I must admit I never though about aliens this way until hearing his speech, but many things
he said made a lot of sense to me. Do you agree?

As more time goes by? Your lifetime is but an insignificant instant in cosmic time, so any non-happening in that time frame should not sway your opinion. Even the time since we have been “modern” humans–100-200,000 years–is insignificant. maybe they are busy in another sector right now.

How easily discernable and by what means? So far, the best way I would know of for telling a brown dwarf from a Dyson system would be to measure for local gravitational distortion effects, since a brown dwarf is, well, a dwarf while a Dyson-sphere-encased star system would be huge.

Yes, that’s “only” 8,000,000,000 planets if you assume that about one in five Sun-like stars has exactly one Earth-like planet. But there are two things you’re overlooking:

1) It’s quite possible to have more than one Earth-like planet in the “Goldilocks zone” for a single star – we very nearly have two in this solar system (Earth and Mars).

2) This analysis only includes the Sun-like stars, and their statement was about planets capable of supporting life. It’s quite conceivable that there are a number of planets orbiting non-Sun-like stars that could support life – especially dwarf stars, which can be extremely long-lived.

I don’t think that the estimate of “several tens of billions” of Earth-like planets in the galaxy is out of range given those considerations – however it admittedly is an estimate based on a relatively small sample (although that sample is growing rapidly), and might easily be off by an order of magnitude. But probably not by two orders of magnitude, so that still says that the number of Earth-like planets in the galaxy is probably somewhere between 1 and 100 billion – which is really quite a lot any way you look at it.

2) we’ve only been finding planets for 20 years and the pace of discovery is ever increasing. Its only a matter of time before we find one with liquid water and the signatures of life (via atmospheric analysis). I’m talking microbial or vegetative life not Little green men.

The question now isnt IF, Its WHEN do we find signs of life.

Unfortunately there is a MUCH larger question to answer with the recent revelations that the conditions for life seem to be rife throughout our galaxy. Where is everyone? AKA the Fermi paradox. One theory is the great filter. It proposes a high probability series of events that makes the emergence of intelligent life or the continued existence of a technological species vanishingly rare.

The argument goes on to say that as the probability for the existence of any type of extraterrestrial life increases the likelyhood of a great filter also increases. The universe may be teeming with life but the vast majority is unintelligent and technological species like us either don’t develop or burn themselves out rather quickly.

Food for thought in light of several recent discoveries which clearly point to the increasing likelihood of extraterrestrial life

How long do you suppose their pitiful attempt at conquering Earth would last once they realize that they have quicksanded their space fleet on a world overcrowded with apex predators who not only find their bodies to be a tasty snack, but are also quick to reverse-engineer their technology, improve on it themselves and turn it against them?

So… the CMBR is really the trace of crystal defects generated as the computronium expands, which would explain the Fermi paradox … so we will all end up as patterns in the Universe brain generated by the primal hologram? Just checking. :)

So we end where we began,
Thoughts in the Cosmic Mind.
There are no defects,
Only exquisite deviations
Expressed physically as
Novel layers of crystals
Epitaxially growing on the surfaces
Of the crystals existing before them
Ever newer generations of an
Ongoing fractal Cosmic Process.